20941521840 has 160 divisors (see below), whose sum is σ = 75928473600. Its totient is φ = 5290479360.

The previous prime is 20941521817. The next prime is 20941521863. The reversal of 20941521840 is 4812514902.

20941521840 is a `hidden beast` number, since 2 + 0 + 94 + 1 + 521 + 8 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (20941521817) and next prime (20941521863).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20941521795 and 20941521804.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 214096 + ... + 296175.

It is an arithmetic number, because the mean of its divisors is an integer number (474552960).

Almost surely, 2^20941521840 is an apocalyptic number.

20941521840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20941521840 is an abundant number, since it is smaller than the sum of its proper divisors (54986951760).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20941521840 is a wasteful number, since it uses less digits than its factorization.

20941521840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 510312 (or 510300 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The spelling of 20941521840 in words is "twenty billion, nine hundred forty-one million, five hundred twenty-one thousand, eight hundred forty".